Basic processes for processing silver halide light-sensitive materials, for instance, color light-sensitive materials are a color developing process and a desilvering process. In the color developing process, the silver halide exposed to light is reduced with a color developing agent to form elemental silver and simultaneously the oxidized color developing agent reacts with a coupler to form dye images. In the subsequent desilvering process, the elemental silver formed during the color developing process is oxidized by the action of an oxidizing agent (in general, referred to as "bleaching agent") and then is dissolved by action of a complexing agent generally referred to as "fixing agent". Only the dye images remain on the color light-sensitive materials through such a desilvering process.
The desilvering process described above generally comprises two processing baths, one of which is a bleaching bath containing a bleaching agent and the other of which is a fixing bath containing a fixing agent; or one bath, i.e., a bleach-fixing bath simultaneously containing a bleaching agent and a fixing agent.
The practical development processing further comprises, in addition to the foregoing basic processes, a variety of auxiliary processes for the purpose of maintaining photographic and physical properties of images, enhancing storability of images or the like. Examples of such auxiliary processes or baths are a film hardening bath, a stopping bath, an image stabilizing bath and a water washing bath.
If a light-sensitive material composed of an emulsion containing silver iodine such as a color negative light-sensitive material for taking photographs is desilvered, it takes a long period of time and, therefore, there is a strong demand to develop a method in which the time required for desilvering can substantially be shortened.
It is also required to reduce the amount of waste liquor derived from photographic processing from the viewpoint of preventing environmental pollution and in the desilvering process, it becomes an important subject to reduce the amount of waste liquor, for instance, by reducing the amount of a fixing solution to be replenished.
Incidentally, there have been conducted various studies to develop a means for recovering silver as a valuable noble metal from bleach-fixing or fixing solutions, for instance, a method for recovering silver by introducing a bleach-fixing solution in an electrolytic cell and then electrolyzing it; a method for recovering silver by diluting the bleach-fixing solution to lower the solubility of a silver salt to precipitate the same; a method for recovering silver by adding sodium sulfide to these solutions in order to form silver sulfide; or a method for recovering silver, in the form of ions, by passing such a solution through a column packed with a large amount of an ion-exchange resin. Such means for recovering silver are detailed in, for instance, Kodak Publication, J-10 (Recovering Silver From Photographic Material), issued by Kodak Industrial Division; J. P. KOKOKU No. 58-22528; J. P. KOKAI No. 54-19496; Belgian Patent No. 869,087; and DEOS No. 2,630,661.
However, these methods are developed to recover silver from bleach-fixing solutions, but not to reuse the solutions obtained after the recovery of silver. Therefore, there are various obstacles to reuse such beach-fixing solutions after desilvering. For instance, the bleach-fixing solutions obtained after the desilvering cannot be reused or it is necessary to add components which are lost during the recovering of silver (addition of a regenerant) to reuse the same. As described above, it has not yet been realized to simultaneously reduce the amount of waste liquor and rapidly carry out the desilvering process while recovering silver.
Accordingly, an object of the present invention is to provide a method for processing silver halide photographic light-sensitive materials, which makes it possible to carry out a rapid fixing process compared with conventional methods and to reduce the amount of waste liquor of a processing solution having fixing ability.